MX2011001293A - Silicone-thermoplastic polymer reactive blends and copolymer products. - Google Patents

Abstract

Silicone-thermoplastic polymer reactive blends and copolymer products are prepared using economical post-reactor reactive mixing, e.g., extrusion. The procedure is based on the ring-opening polymerization of cyclic siloxanes within a thermoplastic polymer matrix. In a preferred mode, the thermoplastic polymer is a polyolefin, optionally containing silane groups that are available for reaction with the silicone polymer that is formed in situ. The resulting materials provide hybrid performance that can extend the range of applications beyond those which are served by thermoplastic polymers or silicones alone, or their physical blends.

Description

REACTIVE MIXTURES OF SILICONE-THERMOPLASTIC POLYMER AND ERIC COPOL1M PRODUCTS Cross Reference to the Sun Relatively Connected j The present application claims priority to the Application for US Patent Serial No. U.S. 61 / 085,638, filed on August 1, 2008, the complete contents of which are incorporated herein by reference.

Field of the Invention j The present invention relates to reactive mixtures of i silicone-thermoplastic polymer and copolymer products. In one aspect, the invention relates to a process for preparing such mixtures and products in which a cyclic silicone is polymerized within a thermoplastic polymer matrix, while in another aspect, the present invention relates to a process in which which the thermoplastic polymer is a polyolefin, optionally conj silane functional groups, and the cyclic silicone is polymerized with the aid of j a ring opening catalyst. j Background of the invention! Silicone polymers are used in a variety of applications, in which they are valuable for their unique combination of Attributes, including thermal stability, ozone resistance and I in the open, oxidative stability, lubricity, repellency i of the water, the low surface tension, its good properties electric, its properties at low temperature, resistance to oil, i I to moisture and steam, chemical resistance and flame resistance. Reactive mixtures and copolymers of silicones and various thermoplastic polymers, particularly polyolefin polymers, can provide a hybrid performance that can extend the range of I applications beyond those for which the thermoplastic polymer or the silicone polymer serves alone, or their mixtures i physical In addition, these mixtures and copolymers offer advantages of performance and / or cost in relation to polymers only of silicone or pure thermoplastic polymers.

The US Patent U.S. US Pat. No. 5,488,087 describes sulfonated polyethylene and octamethylcyclotetrasiloxane, in which the sulfonate groups in the polyethylene catalyze the ring opening polymerization of the siloxane. The reaction rates are very slow, requiring weeks to achieve extensive polymerization levels, and the reference does not teach or suggest any mechanism for grafting the resulting silicone into the polymer.

U.S. Patent Application Publication. 2006 / U21 7460 discloses compositions comprising various polyolefins, a flame retardant: inorganic, and a silicone which may be cyclic. The cyclic silicone is provided to coat the surface of the I Flame retardant. The composition does not include a polyolefin that I comprises grafted silanes, and does not suggest that silicone grafts be made to the polyolefin in the polymerization, to form a siloxane p-polymer. In addition, the process for preparing the siloxane polymer does not include a catalyst. Even more, the coating of Flame retardant silicone is formed before adding the I flame retardant to polyolefin. 1 U.S. Patent Application Publication. 2006/0223943 discloses a grafted polyolefin copolymer produced in the presence of a coordinated polymerization catalyst with a transition metal complex, by graft copolymerization of an olefin monomer with a silicone macromonomer produced by emulsion polymerization. The silicone macromonomer is produced by the reaction of an organosiloxane with a compound that has in its molecule, a group i functional reactive with the organosiloxane. j The US Patent U.S. 5,854,356, describes j polyolefins with silicone grafts prepared by the composition of silicones with reactive polyolefins comprising an ethylene / vinyltrimethoxysilane copolymer or an ethylene / hydroxyethyl methacrylate copolymer. The polyolefins with resulting silicone impregnation exhibit excellent release properties (low adhesion), which can be further improved by using dibutyltin dilaurate as a condensation catalyst. Polyethylene blends with silicone functional groups with polyethylene i unmodified, they also exhibit release properties. | The US Patent U.S. No. 6,054,548 describes phosphazene-based catalysts useful for the ring-opening polymerization of cyclic silicones. The use of such catalysts j with silicones within a polyolefin matrix, is not described.

Improved processes for preparing reactive mixtures of silicone-thermoplastic polymer and copolymer products are desirable, using economical equipment of post-reactor composition and / or extrusion. The present processes for preparing such reactive mixtures are limited, and include chemistry in the reactor or reactive composition of an incompatible mixture of a thermoplastic polymer and a polymer of high molecular weight silicone, difficult to handle. j I Brief Description of the Invention! The mixtures [reactive silicone-thermoplastic polymer and copolymer products, are prepared using an economical reactive mixture after the reactor, for example, extrusion. The process is based on the polymerization with opening of cyclic siloxane ajonillo within a thermoplastic polymer matrix. In a preferred embodiment, the thermoplastic polymer is a polyolefin, optionally containing silane groups that are available to react with the silicone polymer that is formed in situ. The resulting materials provide a hybrid performance that can extend the range of applications beyond those for which thermoplastic polymers or silicone polymers serve alone, or their physical blends. In addition, they offer performance and / or cost advantages over thermoplastic polymers or pure silicone polymers. In one embodiment, the process employs a catalyst based on phosphazene. In another modality, the process I comprises the in situ reaction of monohydroxysilicone with a polymer with silane functional groups. j In one embodiment, the invention is a process for preparing a reactive mixture comprising a silicone polymer within ! a thermoplastic polymer matrix, wherein the process comprises the steps of (A) forming a mixture of a cyclic siloxane and a thermoplastic polymer, and (B) subjecting the mixture to conditions under which the cyclic siloxane is polymerized to form a polymer of silicone. Preferably, the cyclic siloxane is polymerized using a catalyst to open the ring.

In one embodiment, the invention is a one-time process i operation for preparing a copolymer product comprising units derived from a thermoplastic polymer, preferably a polyolefin polymer, a silane crosslinker and a silicone polymer, wherein the process comprises the steps of (i) contacting the silane crosslinker with the thermoplastic polymer, under grafting conditions, such that the silane crosslinker is grafted onto the thermoplastic polymer, and (ii) adding a cyclic siloxane to the thermoplastic polymer with silane grafts, under polymerization conditions of the cyclic siloxane, such so that the silicone polymer is formed and reacts with the thermoplastic polymer with | Silane grafts. In a variation of this embodiment, the first and second steps are performed in a long extruder, the first step being performed in a graft zone and the second step in a ring opening polymerization zone. In another variation of this mode, the steps of grafting and ring opening / polymerization are Detailed Description of the Preferred Modality All references to the Periodic Table of the Elements refer to the Periodic Table of the Elements published by, and copyrighted by, CRC Press I nc. 2003. Likewise, any reference to a group or groups, will be to the group or groups reflected in this Periodic Table of the Elements, using the system of the IUPAC to number the groups. Unless stated otherwise, be implicit in the context, or customary in the i technical, all parts and percentages are based on [weight and i all test methods are current as of the presentation date i of the present description. For the purposes of patent practice in the United States, the content of any patent, patent application or patent publication referred to herein is incorporated herein in its entirety as a reference (or equivalent version thereof). US, also incorporated by reference), especially with respect to the description of synthesis techniques, definitions (to the extent that they are not inconsistent with any definition specifically provided in the present description) and general knowledge of the art.

I The ranges! Numbers in the present description are approximate, and may therefore include values outside the range a unless indicated otherwise. Numerical ranges include all values from and including the lowest value and the highest value, in increments of one unit, as long as there is a separation of at least two units between any lower value and any higher value. As an example, if a property I of the composition, physical or other property, such as for example the melt index or melting temperature, is from 100 to 500, awnings the individual values, such as 100, 101, 102, etc., and sub-ranges, such as 100 to 144, from 155 to 170, from 197 to 200, etc, are expressly listed. For ranges that contain values less than 1 or that contain fractions greater than 1 (for example, 1 .1, 1 .5, etc.), one unit is considered 0.0001, 0.00; 0.01 or 0.1, as appropriate. For ranges containing single-digit numbers under 1 0 (for example, from 1 to 5), a unit is typically considered to be 0.1. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value listed, are considered to be expressly stated in the present description. Numerical ranges are provided! in the present description for, among other things, the density, melt index, cyclic siloxane content, thermoplastic polymer and / or catalyst of the reaction mixtures and products, the graft content of the thermoplastic polymer, and various parameters of the process.

The term "comprises" and its derivatives do not exclude the presence of any additional component, step or procedure, whether or not the same as that being specifically described. In order to avoid any doubt, all compositions claimed by the use of the term "comprises" may include any additive, adjuvant or additional compound, whether polymeric or not, unless otherwise indicated. In contrast, the term "consisting essentially of" excludes from its scope any subsequent mention of any other component, step or procedure, except those that are not essential for operability. The term "consisting of" excludes any component, step or procedure that was not specifically delineated or listed. The term "or", unless otherwise specified, refers to the members listed individually, as well as in any combination. \ As used with respect to a chemical compound, unless specifically indicated otherwise, the singular includes all isomeric forms and vice versa (for example, the term "hexane" includes all isomers of hexane individually or collectively). The terms "compound" and "complex" are used interchangeably to refer to organic, inorganic and organometallic compounds. The term "atom" refers to the smallest component of an element, regardless of its 'I ionic state; that is, whether it is a carrier or not of a partial load or load or that is linked to another atom. The term I "amorphous" refers to a polymer that lacks a crystalline crystallization point, determined by Differential Scanning Calorimetry (CDB) or an equivalent technique. j i The term "composition" and similar terms mean a mixture of two or more materials. The compositions include pre-reaction mixtures, reaction mixtures and post-reaction mixtures, where the latter will include the reaction products and any by-products, as well as the unreacted components of the reaction mixture and the products. of decomposition if any, formed from one or more components of the mixture prior to the reaction or the mixture of ! I I reaction. j The term "mixture", "polymer mixture" and similar terms, mean a composition of two or more polymers. Such a mixture may or may not be miscible. Such a mixture may or may not be separated in phases. Said mixture may or may not contain one or more domain configurations, as determined by Electron Transmission Spectroscopy, Light Scattering, X-Ray Dispersion and any other method known in the art.

The terms "reactive mixture", "mixture in the reactor" and i similar terms, \ mean a reaction product prepared from a reaction mixture of two or more components! of which at least one reacts in the presence of one or more of the other components, or all the components react essentially at the same time. The components can react with themselves, as in the case of homopolymerization, or with one or more of the other components, as in the case of the i copolymerization or grafting. In the context of the present invention, an example of a reaction mixture, is a reaction product comprising polyolefin and silicone polymers, wherein the silicone polymer was formed in the presence of the polyolefin polymer; that is, the polyolefin polymer was a component of the reaction mixture in which the silicone polymer was formed. Another example of a reactive mixture in the context of the present invention is a reaction product comprising a polyolefin polymer grafted with silane and a silicone polymer therein which both the silane-grafted polyolefin polymer and the silicone polymer are formed at the same time and / or from the same í reaction mixture. The terms "physical mixture", "physical polymer blend" and the like, mean a polymeric mixture subsequent to the reactor; that is, a mixture that is the result of mixing two or more polymers under conditions in which the polymers do not react with each other. In a physical mixture, the polymeric components are physically intermingled with one another and do not react with each other to form new larger molecules.

The term "copolymer product" and similar terms, mean a product that is formed from the reaction of two or more monomers or polymers, with each other. In the context of the present invention, an example of a copolymer product is the product formed by the reaction of a silicone polymer with a polyolefin polymer with silane functional groups.

The terms "reaction mixture", "reaction mass" and I similar terms, mean the combination of necessary or auxiliary materials for a reaction, typically under reactive conditions. In the course of a reaction, a reaction mixture is converted into a product mixture. Depending on the time at which the reaction mixture is characterized and other factors such as whether the process is batch or continuous, the physical condition of the raw materials and the product, etc., may contain or contain the reagents, catalysts, so, i processing aids, products, by-products, impujrezas and the like. > The term "product mix" and similar terms means ! the combination of materials that are the result of subjecting a reaction mixture to the reaction conditions. A product mix will always contain some product and / or by-product and, depending on a multiplicity of factors (for example, batch versus continuous process, physical state of raw materials, etc.), ! it may or may not contain raw materials that did not react, catalysts, solvents, processing aids, impurities, and the like.

The term "reaction conditions" and similar terms generally refer to temperature, pressure, concentration of I reagents, catalyst concentration, cocatalyst concentration, mixed with or without cutting, and the like, which transform a reaction mixture into a product mixture. The reaction conditions influence not only the reaction and transformation rate, and the selectivity of the initial reagents for ; Forming reaction products, but also often] have an influence on the properties of the reaction products. j The term "ring opening conditions" and similar terms mean reaction conditions necessary to open the ring of a cyclic siloxane within a thermoplastic polymer matrix. These conditions will vary according to the polymer matrix, the nature and structure of the siloxane, the presence or absence of a catalyst for opening the ring, the presence or absence of processing additives, and the like.

The term "polymerization conditions" and similar terms, I mean the reaction conditions necessary to combine i monomers in polymers. In the context of the present invention, these conditions are those necessary for the cyclic siloxanes with the open ring to combine with others to form a i silicone polymer inside a polymeric matrix. j The term "polymer" means a polymeric compound prepared by the polymerization of monomers, either | same i or of a different type. The generic term polymer, therefore, encompasses the term homopolymer normally used for i refer to polymers prepared from a single type of monomer, and also encompasses the term interpolymer as i define later. It also covers all forms of interpolymers, for example, random, blocks, and so on. The terms "ethylene / alpha-olefin polymer", "polymer of j propylene / alpha-olefin "and" silane copolymer "are indicative of I interpolymers as previously described. ? The term "interpolymer" means a polymer prepared by the polymerization of at least two different monomers. This generic term includes copolymers, (term commonly used to refer to polymers prepared from two different monomers, and polymers prepared from more than two different monomers, for example, terpenemers, tetrapolymers, et cetera. | The term "catalytic amount" and similar terms mean i an amount of catalyst sufficient to promote the reaction rate between two or more reagents, to a discernible degree! In the context of the present invention, a catalytic amount is the amount of catalyst needed to promote the polymerization rate of the cyclic siloxane, or the reaction rate of the cyclic siloxane. ; i siloxane with the silane group in the polymer matrix. ! The term "amount of crosslinker" and similar terms, i means an amount of a crosslinking agent or radiation or I moisture, or any other cross-linking compound or energy, sufficient to impart at least a detectable amount (by a recognized method, for example extractable xylenes, etc.), of crosslinking in the composition or mixture, under conditions j reticulators. j Thermoplastic Polymer \ Any thermoplastic polymer that will form a matrix within which a cyclic siloxane can be polymerized can be used in the practice of the present invention. Preferably, the thermoplastic copolymer can have silane functional groups. Thermoplastic polymers are characterized by their ability to melt at I a liquid state when heated and frozen in a state I brittle and vitreous when they get cold enough. Many Thermoplastic polymers are high molecular weight and comprise and associated chains through weak Van der Waal forces (for example, polyethylene); and / or exhibit strong bipolo-bipolo interactions, and hydrogen bonds (e.g., nylon) and / or even exhibit the stacking of aromatic rings (e.g., polystyrene). Thermoplastic polymers differ from thermomixable polymers (for example, vulcanized rubber), because they can, unlike thermosetting polymers, be remelted and re-melted. i mold. Many thermoplastic materials are addition polymers; for example, increasing vinyl chain polymers, such i such as polyethylene and polypropylene. Some representatives of thermoplastic polymers, include but are not limited to polyesters, polycarbonates, polyurethanes, nylon, polyvinyl chloride and polyolefins. , j A particularly preferred class of thermoplastic polymer useful as a matrix polymer in the practice of the present invention are polyolefins. These thermoplastic polymers include both homopolymers and polyolefin interpolymers. Examples of polyolefin homopolymers are ethylene and propylene homopolymers. Examples of polyolefin interpolymers are the ethylene / o-olefin interpolymers and the interpolymers of propylene / α-olefin. The α-olefin is preferably an α-olefin of 3 I to 20 carbon atoms of straight, branched or cyclic chain (for propylene / α-olefin interpolymers, ethylene is considered I like the α-olefin. Examples of α-olefin of 3 to 20 atoms Carbon includes propene, 1-butene, 4-methyl-1-pentene, 1-hexene, i i 1 - . 1-octene, 1 -decene, 1 -dodecene, 1 -tetradecene, 1 -hexadecene and 1-octadecene. The α-olefins may also contain a cyclic structure such as cyclohexane or cyclopentane, resulting in An α-olefin such as 3-cyclohexyl-1-propene (allylcyclohexane) and vinylcyclohexane. Although they are not - olefins in the classical sense of j term, for the purposes of the present invention certain cyclic olefins, such as norbornene and related olefins, j are α-olefins and may be used in place of one or all of the a-olefins described above. Similarly, styrene and I 3 its related olefins (e.g., α-methylstyrene, etc.) are α-olefins for the purposes of the present invention. ^ some Exemplary polyolefin copolymers include ethylene / propylene, ethylene / butene, ethylene / 1-hexene, ethylene / 1-ketene, ethylene / styrene copolymers, and the like. Some illustrative terpolymers include ethylene / propylene / 1-jotene, ethylene / propylene / butene, ethylene / butene / 1-ketene terpolymers,! Y ethylene / butene / styrene. The copolymers can be random or block.

The polyolefin can also be a copolymer comprised of ethylene and unsaturated esters or acids, and these polyolefins are known and can be prepared by the techniques of conventional Unsaturated esters can be alkyl, alkyl methacrylates or vinyl carboxylates. alkyl can have from 1 to 8 carbon atoms and they have from 1 to 4 carbon atoms. The carboxylate groups can have from 2 to 8 carbon atoms and preferably have from 2 to 5. ! carbon atoms. The portion of the copolymer attributed to the ester comonomer may be in the range of 1 to 50% by weight, based on the weight of the copolymer. Examples of acrylates and methacrylates are ethyl acrylate, methyl acrylate, methyl methacrylate, t-butyl acrylate, n-butyl acrylate, n-butyl methacrylate and 2-ethylhexyl acrylate. Examples of vinyl carboxylate.j are vinyl acetate, vinyl propionate and vinyl butanoate. Examples of unsaturated acids include acrylic acids or maleic acids.

More specific examples of useful olefinic interpolymers in the present invention include very low density polyethylene (PEMBD) (eg, FLEXOM ER® ethylene / 1-hexene polyethylene prepared by The Dow Chemical Company), ethylene copolymers linearly branched, homogeneously branched olefin (for example, TAFMER® from Mitsui Petrochemicals Company Limited and EXACT® from Exxon Chemical Company), homogeneously branched etjlene / cc-olefin polymers, substantially linear chain (for example AFFI NITY® and ENGAGE® polyethylene available from The Dow Chemical Company) and jolefin block copolymers, such as those described in US Pat. 7,355,089 (for example I N FUSE® available from The Dow Chemical Company). The most preferred polyolefin copolymers are homogeneous linear chain ethylene copolymers branched and substantially linear chain. The substantially linear chain ethylene ethylene copolymers are especially preferred, and are described in greater detail in the Fjatentes North American US 5,272,236; 5,278,272 and 5,986,028. | i Polyolefin copolymers useful in the practice of the present invention also include copolymers of propylene, butene and other copolymers based on alkenes, for example copolymers comprising a majority of propylene derived units and a minority of units derived from another ot-olefin i (including ethylene). Examples of propylene polymers useful in the practice of the present invention include polymers VERSIFY® available from The Dow Chemical Company and the VISTAMAXX® polymers available from ExxonMobil Chemical Company.

Mixtures of either j of the above olefinic interpolymers can also be employed in the present invention, and the polyolefin copolymers can be mixed or diluted with one or more other polymers to a degree where, in a preferred embodiment, the copolymers of polyolefin of the present invention constitute at least about 50, preferably at least about 75 and more preferably at least about 80 weight percent of the thermoplastic polymer component of the blend.

Polyolefins, particularly ethylene polymers useful in the practice of the present invention, typically have, prior to graft, a density less than 0.965, preferably less than 0.93 grams per cubic centimeter (g / cm3). The copolymers of | ethylene I they typically have a density greater than 0.85, preferably greater than 0.86 g / cm3. The density is measured by the procedure of ASTM D-792. In general, the larger the α-olefin content of the interpolymer, the lower the density and the more amorphous the interpolymer will be. The density polyolefin copolymers are generally characterized as semi-crystalline, flexible, and having good optical properties, for example a high transmission of visible light and UV light, and low opacity.

The ethylene polymers useful in the practice of the present invention typically have, before grafting, a melt index greater than 0.10 and preferably greater than 1 gram per 10 minutes (g / 10 minute). Ethylene polymers typically have a melt index of less than 500 and preferably less than 1 00 g / min. The melt index is measured by the procedure of Standard AjSTM D-1238 (1 90 ° C / 2.16 kg). j Preferably, the polyolefin resins used in the practice of the present invention contain alkoxysilane groups (also known as silane crosslinkers). Typically, Alkoxysilane groups are grafted onto a polyolefin resin. In the practice of the present invention, any silane which is effectively grafted and reacted with a silicone polymer can be used. Suitable silanes include unsaturated silanes which comprise an ethylenically unsaturated hydrocarbyl group, such as a vinyl, allyl, isopropenyl, butenyl, cyclohexeneyl or y- (meth) acryloxy allyl group, and a hydrolyzable group such as for example a hydrocarbyloxy, hydrocarbonyloxy, or hydrocarbylamino group. Examples : Hydrolyzable groups include methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, and alkyl or arylamino groups. Preferred silanes are the unsaturated alkoxy silanes that can be grafted; in the i polymer. These silanes and their method of preparation are described in i more detail in the US Patent US 5,266,627. | The vinyl ; i trimethoxy silane, vinyl triethoxy silane, and- (meth) acryloxypropyltrimethoxy silane and mixtures of these silanes, are the preferred silane crosslinkers for use in the present invention.

Alternatively, copolymers of! silane, for example SILINK ™ poly (ethylene-co-vinyltrimethoxy silane) copolymer instead of, or in combination with, olefin polymers grafted or otherwise modified with alkoxy silane groups. | The silane crosslinker is grafted to the polyolefin by any conventional method, typically in the presence of a free radical initiator, for example peroxides and azo compounds, or by ionizing radiation. Organic initiators are preferred, such as any peroxide initiator, for example dicumyl peroxide, di-ferf-butyl peroxide, t-butyl perbenzoate, benzoyl peroxide, eumenohydroperoxide, t-butyl peroctpate, peroxide of methylethyl ketone, 2,5-dimethyl-2, peroxy) hexane, lauryl peroxide, and ferf-butyl peracetate. A i Suitable azo compound is azobisisobutyl nitrile. The amount of initiator may vary, but is typically present in an amount of at least 0.02, preferably at least 0.03, phr. Typically, the initiator does not exceed 0.1 5, preferably does not exceed about 0.1 0 phr. The ratio of silane crosslinker to initiator can also vary widely, but typically the ratio of crosslinker / initiator is between 1: 1 and 1 50: 1, preferably between 1 8: 1 and 1 00: 1. , Although any conventional method can be used to I grafting the silane crosslinker into the polyolefin, a preferred method is to mix the two with the initiator in the first stage of an extruder i I reagent, such as a Buss mixer. Graft conditions may vary, but for polyethylene the temperatures of i melt processing for grafting, typically are between 1 60 and 260 ° C, preferably between 1 90 and 230 ° C, depending on the residence time and the half-life of the initiator. \ I The amount of silane crosslinker used in the practice of the present invention, either as a grafted group in a polyolefin structure, or as a unit incorporated in the (polymeric chain i as a silane copolymer, can vary widely, depending on the nature of polyolefin or silane copolymer, silane, processing conditions, graft efficiency, final application, and individual factors, but typically at least 0.2 are used, preferably at least 0.5% by weight, based on the weight of the copolymer.

Considerations of convenience and economy are usually the two main limitations on the maximum amount of silane crosslinker used in the practice of the present invention, and typically the maximum amount of the silane crosslinker does not exceed 5, preferably not exceeding 3% by weight. weight, based on the weight of the copolymer.

Cyclic siloxanes.

The raw materials for the polymerization reaction with I Ring opening are cyclosiloxanes (also known as cyclic siloxanes). Cyclic siloxanes that are useful are well known and commercially available materials. These have the general formula (R2SiO) n, where R denotes a hydrogen atom or an optionally substituted alkyl, alkenyl, aryl, alkaryl or aralkyl radical, having up to 20 carbon atoms, denotes a whole number with a value of from 3 to 12. R can be substituted, for example, with halogen, such as fluorine or chlorine. The alkyl group can be, for example, methyl, ethyl, n-jpropyl, trifluoropropyl, n-butyl, sec-butyl and fer-butyl. The alkylenyl group can be, for example, vinyl, alkyl, propenyl and butenyl. The aryl and aralkyl groups can be, for example, phenyl, jtolyl and benzyl. Preferred groups are methyl, ethyl, phenyl, vinyl and trifluoropropyl. Preferably, at least 80% of all the R groups are methyl or phenyl groups, more preferably, methyl. Even more preferably, substantially all R groups they are methyl groups. Preferably, the value of n is 3 a! 6, more preferably 4 or 5. Examples of suitable cyclic siloxanes are hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, penta (methylvinyl) cyclopentasiloxane, tetra (phenylmethyl) cycloetrasiloxane and pentamethylhydroxycyclopenta siloxane. A commercially available and particularly suitable material is a mixture of octamethylcyclotetrasiloxane and decamethylcyclopentasiloxane. When R is methyl, the compound is referred to as Dn; for example, when n = 4 the compound is called D4 or D4. j Suitable cyclic starting materials include cyclosiloxanes comprising different siloxane units, as well as other cyclic compounds, which, in addition to the siloxane portion, also have other atoms or groups of atoms in their | rings Some examples include the following three known cyclic compounds.

Catalyst In principle, any phosphazene base is suitable for use as a ring opening catalyst in the present invention. Phosphazene bases have the structure of a nucleus I P = N, where the valences of free N are linked to h, a hydrocarbon, -P = N or = P-N, and the valences of free P are linked to -N or -N. A wide variety of suitable phosphazene bases have been described, in Schwesinger et al., Llebigs Anri. 1996, 1055.1081. Some phosphazene bases are commercially available from Fluka Chemie AG, Switzerland. The phosphazene phases of i preferably have at least three P atoms. Some preferred phosphazene bases have the following general formulas: ((2N) 3P = N-) X (R12N) 3-XP = NR2 . { ((R 2 N) 3 P = N-) x (R 12 N) 3. x P-N (H) R 2} +. { TO} -. { ((R12N) 3P = N-) and (R 2N) 4-yP} +. { TO} -. { (R12N) 3P = N- (P (NR12) 2 = N) 2-P + (NR12) 3} . { TO} "where Ri, which may be the same or different in each position, in a hydrocarbon atom or a hydrocarbon radical optionally i substituted, preferably an alkyl group of 1 to 4 carbon atoms, or wherein two Ri groups bonded to the same N-core can be joined to form a heterocyclic ring, preferably a 5- or 6-membered ring; R2 is a hydrogen atom or an optionally substituted hydrocarbon group, preferably an alkyl group of 1 to 20 carbon atoms, more preferably an alkyl group of 1 to 10 carbon atoms, x has a value of 1, 2 or 3, preferably 2 or 3; and has a value of 1, 2, 3 or 4, preferably 2, 3 or 4; z is an integer from 1 to 10, preferably 1, 2 or 3 and a is an anion, preferably fluoride, hydroxide, silanolate, ajkoxide, carbonate or bicarbonate.

The compounds of the formula. { (R12N) 3P = N- (P (NN) 2- P + (NR12) 3} . { TO} "can be prepared by a method comprising reacting a straight-chain phosphonitrile halide, preferably chloride, with a compound selected from the group consisting of a secondary amine, a metal amide and a quaternary ammonium halide, for form a phosphazene and aminated material, which is followed by an ion exchange reaction that replaces the anion with a nucleophile. i phosphonitrile and the methods for preparing them are known in the art; for example, a particularly useful method includes the reaction of PCI5 with NH4CI, in the presence of a suitable solvent. Secondary amines are the preferred reagent for the reaction with the phosphonitrile halide, and a suitable secondary amine has Í the formula R32NH, wherein R3 is a hydrocarbon radical having up to 10 carbon atoms, or both R3 groups form a heterocyclic group with the nitrogen atom, for example a pyrrolidino group, a pyrrole group or a pyridine group. Preferably, R3 is a lower alkyl radical, more preferably a methyl group, or both R3 groups form a pyrrolidine ring. Preferred secondary secondary compounds include dimethylamine, diethylamine, dipropylamine and pyrrolidine. Preferably, the reaction is carried out in the presence of a material that is capable of capturing the interchanged halides, for example an amine such as triethylamine. The resulting by-product (for example, triethylammonium chloride) can subsequently be removed from the reaction mech, for example by filtration. The reaction can be in the presence of a suitable solvent for the phosphonitrile chloride and the straight chain phosphazene base. Suitable solvents include! aromatic solvents such as toluene. He j linear chain phosphazene material which is formed in this way, subsequently must be subjected to an ion exchange reaction (preferably in an ion exchange resin), wherein the anion is replaced by a hard nucleophile, preferably a hydroxyl radical or alkoxy, more preferably, hydroxyl) '. Suitable ion exchange systems include any known ion exchange system, for example, exchange resins Ionic, and no detailed description is provided. The phosphazene is preferably dispersed in a suitable medium before passing through an ion exchange system. Suitable media include water, alcohol and mixtures thereof. In particularly preferred phosphazene-based compounds for use in the present invention, R 1 is a methyl radical, R 2 is a ferf-butyl or ferf-octyl radical, x has a value of 3, and has an i value of 4. , it is already fluoride or hydroxide.

Process The process of the present invention is the preparation of reactive mixtures and copolymers of silicones and thermoplastic polymers, by carrying out a ring-opening polymerization of cyclic siloxanes, inside a thermoplastic polymer matrix. The process itself can follow one of when, minus three lines. In one line, a cyclic siloxane is added to a : I thermoplastic polymer, under ring opening conditions, and the cyclic siloxane undergoes the polymerization, thereby forming a reactive mixture of polymerized thermoplastic polymer and siloxane; that is, the silicone polymer. This thermoplastic polymer component of this reactive mixture, optionally can be crosslinked by standard crosslinking techniques, for example, if the thermoplastic polymer is a polyolefin, then the polyolefin is contacted with a peroxide, under crosslinking conditions. The ring opening of the cyclic siloxane can be facilitated by the use of a ring opening catalyst.

In a second line, a cyclic siloxane is added to a thermoplastic polymer with silane functional groups, for example, a polyolefin, under conditions of ring opening, i cyclic cyclosiloxane undergoes polymerization, thereby forming a silicone polymer, and the silicone polymer then reacts with the silane groups of the thermoplastic polymer, thereby forming a reactive copolymer product. The conditions necessary to promote the reaction between the silicone polymer and the silane groups of the thermoplastic polymer are essentially the same as those necessary to promote the ring opening of the cyclic siloxane. As in the first line, the opening of the The ring of the cyclic siloxane can be facilitated by a ring opening catalyst, and the thermoplastic polymer matrix can be crosslinked, typically after the reactive copolymer product has been recovered from the reaction mixture. j In a third line, a cyclic siloxane and a silane crosslinker are added to a thermoplastic polymer, under conditions of ring opening and silane grafting (in this case, the conditions for ring opening and the conditions for grafting the ring). silane are the same), the cyclic siloxane is polymerized while during this same operation the silane crosslinker is grafted onto the thermoplastic polymer, and then the silicone polymer reacts with the silane groups of the thermoplastic polymer, i to form a reactive copolymer product . Like in the first and second lines, the polymerization of the cyclic siloxane can be facilitated with a catalyst, and the matrix of the thermoplastic polymer, optionally, can be cross-linked, typically after the reactive copolymer product has been recovered from the reaction mixture. i While the equipment used to prepare the reactive mixtures and the copolymer products is not critical to the invention, typically these products are prepared in a mixing apparatus that imparts cut to the reaction mixture. Examples of mixing equipment are internal batch mixers, such as I an internal Banbury ™ or Bolling ™ mixer. Alternatively, continuous mixers or twin screw mixers can be used, such as the Farrel ™ continuous mixer, a I Werner and Pfleiderer ™ 'twin screw mixer, or a : i continuous extruder with Buss ™ mixer. The type of mixer used and the operating conditions of it, will affect the properties of the composition such as viscosity, resistivity and uniformity of the extruded surface. i The thermoplastic polymer typically already containing the silane functional groups, is fed to the extruder, followed by the cyclic siloxane and, if used, the ring opening catalyst, ! as well as any other process additive that could be used. The reaction mixture is subjected to the ring opening conditions, including a temperature between the melting point of the I thermoplastic polymer and 200 ° C (for polyolefins), depending on the temperature of the extract of a number of different variables, where one of them is whether the ring opening will occur during mixing, processing or after processing. The pressure may vary from subatmospheric to superatmospheric In a reaction extruder, the pressure may approach or exceed 10,000 psi (70 megaPascals, mPa), whereas in an open batch mixer, the pressure is typically ambient (0.1 mPa) ).

If the silane graft of the thermoplastic polymer is made in the same operation in which the siloxane ring is opened and polymerized, then this can be done by one of two methods. One method is to use a long extruder that is equipped with a silane graft zone, followed by a ring opening / polymerization reaction zone. Alternatively, the silane and silicone grafting reactions may occur more or | less simultaneously. However, the preferred mode from the point of view of technical control over chemistry, is to start with a polymerizer.

I thermoplastic that already has silane functional groups, such as the SI-LINK ™ copolymer or PE-g-VTMS (grafted polyethylene with vinyl trimethoxysilane).

The amount of cyclic siloxane in the reaction mixture, I typically it is between 0.1 and 85, preferably between 0.2 and! 20 weight percent (% by weight), based on the weight of the reaction mixture. The amount of thermoplastic polymer in the I reaction is typically between 15 and 99.9, preferably between 10 and 95% by weight, based on the weight of the reaction mixture. The amount of catalyst in the reaction mixture, if present, i it is between 10 parts per million (ppm) and 5% by weight, based on the weight of the reaction mixture.

In those cases where relatively high levels are desired, for example at least 5% by weight based on the combined weight of the thermoplastic polymer and the silicone polymer, of silicone, in the reactive polyolefin-silicone blends or copolymers, the addition of the cyclic siloxanes in multiple doses could be desirable, to allow the first doses to partially or completely react in the system before adding more cyclic silicone. This helps avoid potential process challenges associated with large amounts of cyclic siloxanes, i many of which are liquid.

Anionic or cationic polymerization with ring opening is possible, and there are options for the kinetic or thermodynamic control of the reaction products, by choosing the silicone, the catalyst and other conditions. Depending on the nature of the initiator, monosilicones or dihydroxysilicone can be formed with or without active anionic end groups. Thus, the resulting silicones and intermediates can easily participate in the functionalization and crosslinking reactions with the thermoplastic polymers and grafted silanes. j The inclusion of silicone functional groups during ring opening j / polymerization can be used to impart additional properties. For example, the inclusion of some silicones with functional groups, vinyl, can be incorporated into the silicone polymer, to facilitate the crosslinking with peroxide. Also I know It is molecular fonts d including hexamethyldisiloxane or short silicones terminated in methyl, which leave M or MM terminal groups together with a few extra D groups. ' The reactive mixtures and copolymers of the present invention, I may contain additional additives, including but not limited to, antioxidants, curing agents, crosslinking coagents, reinforcers and retardants, processing aids, fillers, coupling agents, ultraviolet absorbers or stabilizing agents, antistatic agents, nuclease agents, sliding agents, plasticizers, lubricants, control agents la viscosity, tackiness enhancers, antiblocking agents, surfactants, extender oils, acid trapping agents and I metal deactivators. Additives in quantities can be used I ranging from less than 0.01 to more than 10% by weight, based on the weight of the composition; that is, the reactive mixture or product copolymer.

Examples of antioxidants are, but are not limited to: hindered phenols such as tetrakis [methylene (3,5-di-ferf-butyl-4-hydroxyhydro-cinnamate)] methane; bis [(beta- (3,5-ditert-butyl-4-hydroxybenzyl) -methylcarboxyethyl)] sulfide, 4,4'-thiobis (2-methyl-6-ferf-butylphenol) J 4,4'-thiobis (2 -ery-butyl-5-methylphenol); 2,2'-thiobis (4-methyl-6-ferf-butylphenol); and thiodiethylene bis (3,5-di-ferf-butyl-4-hydroxy) -diocinamate; phosphites and phosphonites such as tris (2,4-di-fert-butylphenyl) phosphite and di-ferf-butylphenyl-phosphonite; thio compounds such as dilaurylthiopropionate, dimyristylthiodipropionate, and distearylthiodipropionate; several silices; 2,2,4-trimethyl-1,2-dihydroquinoline pol imetizated a, n, n'-bis (1,4-dimethylpentyl-p-phenylenediamine), alkylated diphenylamines,! 4,4'-bis (alpha, alpha-demethylbenzyl) diphenylamine, diphenyl-p-phenylenediamine, mixed di-aryl-p-phenylenediamines, and other antidegradants or hindered amine stabilizing agents. Antioxidants may be used in amounts of 0.1 to 5% by weight, based on the weight of the composition. j Examples of curing agents (for example, crosslinking initiators for a polyolefin) are as follows: dicumyl peroxide; bis (alpha-t-butyl peroxyisopropyl) benzene; isopropylcumyl-t-butyl peroxide; t-butylcumyl peroxide; di-t-butyl peroxide; 2,5-bis (t-butylperoxy) 2,5-dimethylhexane; 2j5-bis (t-butylperoxy) 2,5-dimethylhexine-3; 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane; isopropylcumyl cumylperoxide; di (isopropylcumyl) peroxide; ] or mixtures thereof. The agents of I peroxide curing can be used in amounts of 0.1 to 5% by weight, based on the weight of the composition. Various other coagents, reinforcers and known cure retardants, such as triallyl isocyanurate; dimetacri ato de bisphenol A ethoxylate; a-methylstyrene dimer; and other coagents described in U.S. Patent Nos. 5,346,961 and 4,018,852. i I Examples of processing aids include, but are not limited to, metal salts of carboxylic acids, such as zinc stearate or calcium stearate; fatty acids such as stearic acid, oleic acid or erucic acid; fatty amides such as stearamide, oleamide, erucamide, or?,? '- ethylenebistearamide; polyethylene wax; oxidized polyethylene wax; ethylene oxide polymers; copolymers of ethylene oxide and propylene oxide; vegetable waxes; oil waxes; nonionic surfactants; and polysiljoxanes. The processing aids can be used in quantities of calcium, zirconium oxide, titanium oxide, zinc oxide, magnesium oxide, magnesium carbonate, calcium carbonate, barium sulfate, barium borate, meta-barium borate, zinc borate! borate I of meta-zinc, aluminum anhydride, molybdenum disulfide clay, I I red phosphorus, diatomimta, kaolinite, montmorilonite, hydrotalcit †, talc, silica, white carbon, celite, asbestos and lithopon. Magnesium hydroxide and aluminum trihydroxide are the preferred flame retardant agents. ! Applications ! The thermoplastic silicone-polymer, particularly silicone-polyolefin, the reactive mixture and prepared copolymer products i by the process of the present invention, they can be used in applications requiring thermal stability, resistance to ozone and weathering, oxidative stability, lubricity, water repellency, low surface tension, good electrical properties, low temperature profiles, resistance to oil, moisture and vapor, chemical resistance and / or flame resistance. Such applications include: spark plugs and jackets for ignition cables, sleeves for the drive shaft of front-wheel drive vehicles, gaskets; seals, i O-rings, protective coatings, as well as radiator and heater hoses for trucks and trucks; insulators and polymeric for transmission, as well as accessories for cables (connectors and terminations, and insulators for exteriors); linings and i insulation for cables, including flame retardant versions.

The reactive mixtures and copolymers of the present invention, they are also useful as compatibilizers. For example, silicones are often added to polyolefins to impart various beneficial properties to them. Typically, silicones are not highly compatible with polyolefins, resulting in poor morphology and exudation. The inclusion of a small amount of one of the copolymers or reactive mixtures of the present invention may result in better morphology in mixtures of silicones and polyolefins. In addition, the inclusion of a small amount of one of these copolymers or reactive mixtures during the reactive processing of silicones with polyolefins, or polyolefins with silane grafts, can provide better reaction rates and morphology because a better mixture can be obtained. as a result of compatibilization. In In some cases, the compatabilizer is first prepared in solution to ensure intimate mixing and morphology. It is possible that only a small amount of such compatibilizer would be required.

Octamethylcyclotetrasiloxane ring-opening polymerization provides a method for forming a siloxane-thermoplastic polymer, particularly copolymers : i grafted with silicone-polyolefin. This method, in some levels, may be superior to the condensation of polydimethylsilane (PDMS) I with silanol endings, because it allows a greater control over the products; of reaction. For example, by starting or catalyzing the reaction with -OH or H +, a bifunctional PDMS chain can be obtained, which is terminated by two hydroxid groups. East product can then react with a polyolefin with grafts VTMS, to form a crosslinked copolymer. On the other hand, simply by selecting a different catalyst (for example, a carbanion), a monofunctional PD S chain can be formed. Then, the chain can be grafted with trimethoxysilane groups while the mixture, as a whole, remains thermoplastic.

The following examples illustrate various embodiments of the present invention. All parts and hundreds are given by weight, unless otherwise indicated. j Specific Modalities j I The degree of polymerization of octamethylcyclotetrasiloxane (D4) of 0.87 g / cm, a melt index of 5 (measured in accordance with ASTM D1238) and available from The Dow Chemical Company, is grafted with VTMS (approximately 1.5 weight percent, based on the weight of the polyolefin) and then impregnated with D4 at 5% until no visible liquid remains. The resulting pellets i they are added to a Brabender mixer at 100 ° C and 45 rpm. The material is left to mix for two minutes before adding 0.1 mL of P4-t-Bu Phosphazene Base 0.25 Molar (M) solution! (1 -ferf-butyl-4,4,4-tris (dimethylamino) -2,2-bis [tris (dimethylamino) phosphoanilidene) amino] -25,45-catenadi) phosphazene) available in Fluka Analytical from j Sigma-Aldrich, Inc.). The D4 is allowed to react for 15 minutes before removing it from the Brabender mixer. One runs í second sample using a temperature of 140 ° C and 0.2 mL of catalyst (0.25M). The mixing procedures (rpm, reaction time) were identical to those of the first sample.

Both experiments showed evidence of the desired reaction. An FTIR was performed on compressed films, and the appearance of a shoulder at approximately 1025 cm "1 is evidjent in i both samples. The FTIR spectrum of the second sample is I presented in Figure 2. The graph above illustrates the initial FTIR, which still shows a substantial amount of D4. The graph of the medium was recorded after allowing the D4 to evaporate overnight. The remaining peak at 1090 cm'1 is attributed to the adsorption of EG 8200 grafted with VTMS (lower graph). | Although the invention has been described in considerable detail i by the foregoing description, drawings and examples, this detail is for illustrative purposes only. Those skilled in the art can make numerous variations and modifications without departing from the spirit and scope of the invention, as described in the appended claims. j

Claims (10)

1. CLAIMS 1. A process to prepare a reactive mixture that i comprises a silicone polymer within a thermoplastic polymer matrix, wherein the process comprises the steps j of (A) forming a mixture of a cyclic siloxane and a thermoplastic polymer, and (B) subjecting the mixture to conditions under which the Cyclic siloxane is polymerized to form a silicone polymer. j 2. A process for preparing a copolymer product that I It comprises units derived from a thermoplastic polymer, a silane crosslinker and a silicone polymer, where the process In such a way that the silane crosslinker is grafted onto the thermoplastic polymer, the cyclic siloxane is polymerized to form the silicone polymer, which, in turn, is combined with the thermoplastic polymer with silane grafts, to form the copolymer product. ! 4. The process of any of claims 1-3, wherein the polymerization of the cyclic siloxane is facilitated with a catalyst. 5. The process of claim 4, wherein the catalyst : i is a phosphazene base. j 6. The process of claim 5, wherein the cyclic siloxane is at least one of the following, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, penta (methylvinyl) -cyclopentasiloxane, i tetra (phenylmethyl) cyclootetrasiloxane and pentamethylhydrocyclopentasiloxane. 7. The process of claim 6, wherein the thermoplastic copolymer is a polyolefin. ! 8. The process of claim 1, wherein the thermoplastic polymer contains silane functional groups. i 9 · The process of claim 2, wherein the first step j it is carried out in a grafting zone of a reaction extruder, and the second step is carried out in a ring opening / polymerization zone of the same reaction extruder. 10. The process of claim 9, wherein the thermoplastic polymer is a polyethylene and the silane crosslinker is [0102] less one of vinyl trimethoxysilane, vinyl triethoxysilan, [alpha] (meth) acryloxy propyl trimethoxy silane, and mixtures of two or more of these silanes.